CONSTRUCTION OF PONDS. 35 



nal course of the stream. At the points A and 

 B dams were erected and the earth removed, form- 

 ing ponds Nos. 2 and 3. Pond No. 1 is exca- 

 vated upon the right bank and connected with 

 the main stream by the race a; b serves both 

 as an outlet for No. 1 and a spawning race for 

 No. 2. Sluice-gates (marked x\ with screens, are 

 placed at proper points. We might go on add- 

 ing plan to plan, ad infinitum, having in our 

 portfolios dozens which we have either designed, 

 or drawn from other sources; but we hope that 

 the two presented will afford our readers a gen- 

 eral idea, which is all that can be expected in a 

 work of the present size. 



The plan of the ponds having been decided 

 upon, the proportionate size of the banks re- 

 quired to retain the water will next occupy the 

 attention of the projector. 



This is a matter of more importance than is 

 generally considered. Moving earth is an expen- 

 sive process, and every cubic yard unnecessarily 

 transported is money lost to the projector ; while 

 if not built of the requisite strength, severe loss is 

 sure to follow. The proportions suggested by the 

 French engineers, and which we have found in 

 every case to be perfectly satisfactory, are as fol- 

 lows : the width at base must be three- times the 

 the height, and the width at top equal to the 



